Existing structures are usually encumbered by wide and complicated spaces in which pillars, girders, and beams are interposed from below ground up to the ceiling.
It has been conventional to employ robots, which are large and heavy in their respective structural parts but which have few extending arms, to work within such wide spaces. Such conventional robots have been so limited in the vertical and horizontal operating ranges that they require frequent relocation as a whole within the space of the structure or building. This is disadvantageous as such movement requires delicate handling least the robot be harmed.
Also, in the conventional working robot, the arms forming the respective structural parts have been large and heavy. As it is necessary to simultaneously drive the respective arms, a plurality of large servomotors or the like as well as a large controlling electric power source are required. Therefore, the price of the robot itself is very high.
Further, in operation not only must the operator must be very experienced, but excessive electric power must be used for the operation to control such large structures, which results in a very high operating cost.